1. Technical Field
The present invention relates to a polymer stabilization alignment (PSA) liquid crystal display panel, and more particularly to a pixel structure of the PSA liquid crystal display panel.
2. Description of the Related Art
With the development of flat panel display technique, flat panel displays, such as liquid crystal displays that have advantages of light weight, small size and low power consumption are becoming more and more popular. However, under a circumstance that a pretilt angle of the liquid crystal is not set, when liquid crystal is rotated, the liquid crystal may irregularly rotate left or right to form a disordered arrangement, and thus a contrast ratio of the liquid crystal display is severely reduced. In order to control the arrangement of the liquid crystal, an alignment film is disposed on an inner side of a substrate plate in a process of making the liquid crystal display. Generally, a rubbing method is widely adopted to form the alignment film. In the rubbing method, a polymer resin film, such as polyimide resin film is rubbed by fabrics or the like along a single direction, thereby enabling the polyimide resin molecules to align in desired directions. However, the alignment film made by the rubbing method has some disadvantages, such as being polluted by impurities, reducing output due to static electricity, and reducing contrast ratio due to the contact while rubbing.
In order to solve above-mentioned problems, various un-rubbing methods that might form an alignment film have emerged, wherein a polymer stabilization alignment method is widely applied for advantages of simple process, low contact pollution, and little light leakage. In the polymer stabilization alignment method, a reactant monomer is mixed into the liquid crystal, and a color filter (CF) substrate and a thin film transistor (TFT) array substrate are positioned on opposite sides of the liquid crystal and fixed together by curing adhesives. Because pixel electrodes of the liquid crystal display have a plurality of slits formed therebetween and aligned in predetermined directions, when a voltage is applied on upside and downside of the liquid crystal, the liquid crystal molecules can be aligned at pretilt angles. In addition, after the reactant monomer is solidified by ultraviolet (UV) curing, a stabilization alignment polymer film having a fixed pretilt angle is formed on an inner side of the CF substrate and/or TFT array substrate.
However, according to a test result of Multi-domain Vertical Alignment (MVA) liquid crystal display panel, an aperture ratio and a brightness of a traditional MVA liquid crystal display panel still remain to be improved, and how to develop along directions of high contrast ratio, little color shift, high luminance, rapid reaction and wide visual angle of the liquid crystal display is still a big subject.